Blog | Thursday, November 17, 2011

QD: News Every Day--Eyes as the window to the rest of the body

The idea that the eyes are a window to the soul traces back through history in many forms, but the idea that the eyes might reveal medical secrets didn't fall far behind the metaphor.

The clues lie on the retina, which reflects the same microvascular changes that might be seen elsewhere in the body from cardiovascular changes and other diseases. The question now is how to associate retinal changes to specific diseases.

To assess potential associations between retinal microvascular changes with disability in performing activities of daily living, researchers conducted a prospective cohort study of 1,487 community-dwelling, disability-free participants in the Cardiovascular Health Study.

The main outcome measure was self-reported difficulty in performing any daily living activity, which was compared to the presence of retinal signs and advanced carotid atherosclerosis, defined by carotid intima-media thickness in the 80th percentile or more or 25% or more stenosis. Results appeared at Archives of Ophthalmology.

During the median follow-up of 3 years, participants with two or more retinal signs had a higher rate of disability than those with fewer than two retinal signs (10.1% vs. 7.1%; adjusted hazard ratio [HR], 1.45; 95% confidence interval [CI], 1.24 to 1.69; P less than .001).

However, retinal arteriolar caliber (when analyzed as a continuous variable) appeared to be inversely associated with disability (HR, 0.95 per 1 standard-deviation [SD] increase in central retinal arteriolar equivalent [19.5 micrometers]; 95% CI, 0.91 to 1.00; P=.06). Retinal venular caliber was not (HR, 1.08 per 1-SD increase in central retinal venular equivalent [17.8 micrometers]; 95% CI, 0.97 to 1.22; P=.17).

"Our study supports the hypothesis that microvascular disease accelerates age-related disability and retinal signs can be useful in understanding mechanisms and predicting outcomes," the authors wrote. "When retinal examination performed for other indications reveals 2 or more retinal signs, a thorough review and optimization of lifestyle habits and risk factors may be reasonable."

Future research should investigate how to best use the information from retinal photography in clinical risk prediction, they continued.